Some students in a Missouri school district were suspended last week because of their clothing.
The students wore shirts with the Confederate battle flag, in honor of a friend who died.
But Nixa School District officials feared the tribute will promote racism.
One year ago, Colby Snider lost his life. To memorialize the 17-year-old, family and friends created a shirt.
"We wanted something that kind of captured a little bit of everything about Colby," his mother, Jodie Snider, said.
But the commemoration turned to controversy because of the Confederate battle flag.
"It's caused us some racial tension in the community," Nixa School District spokesman Zac Rantz said. "And because of that, we have a school policy that the Confederate battle flag is not allowed, along with the swastika is not allowed on clothing or any items in the school district."
School officials implemented the policy nearly 20 years ago.
"We had the harassment of some minority families, some students driving around with the Confederate flag in the back of their truck threatening and harassing families," Rantz said. "We had lockers defaced, we had a noose hung from a bridge with an effigy on it, we had nooses hung from rearview mirrors."
The race-related harassment also happened in 2013.
"It's been used in a threatening manner against our students," Rantz said. "And it's still used in that manner up until this very school year."
"We put 'Heritage not Hate' on the shirt for a reason," Jodie Snider said. "It just means simply we don't hate anyone. It's about being southern and having pride in who you are and standing up for what you believe in. I've seen kids where it's okay to be gay shirts, so I don't understand how that's not a target. But the rebel flag is."
Snider lost his life to carbon monoxide poisoning. So far, the family has sold nearly 300 shirts.
The school board reviews the clothing policy every year.
Students and parents are invited to speak about the issue at the next school board meeting Thursday.